Relay



J. C. LINDNER ,RELAY 'July 10, 1928. 1,676,340

Filed April 30, 1923 lg J INVENTOR.

Patented July 10, 1928.

Fries.

PATENT Jean 0. LINDN'ER, OF nocrinsrnn, NEW YORK, ASSIGNOR TO GENERAL ,BAILWAY SIGNAL COMPANY, or earns, NEW YORK, aconronarrron on EW YORK.

RELAY.

Application filed April 30, 1923. serial No. 635,666.

This invention relates to protective de-' vices for electric interlocking systems, and partiizularly to deviccswhich are sometimes termed cross protection relays and are used to protect interlocking systems against improper operation of traflic controlling devices, due to crosses between operatingwires and similar derangements of. wiring and connections.

In systems of this kind, the distant traiiic controlling devices, such as signals, derails and switches, are often operated electrically. To assure that such traffic controlling devices are notimproperly operated due to a short, a crossedwire, or a ground, suitable circuit arrangements are provided whcrcbyif a cross or ground occurs which allows a flow of current tendingto operate such a tratiic controllingdevice improperly, such a cross or ground also causes current to flow through a certain circuit portion in a direction opposite to that in which current ordinarily flows in that portion of the system, so that theprovision of a suitable eiectroa'esponsive device in this circuit portion of the system which is responsive to reverse current only may be utilized to disconnect the main source of current, and in this way assure the prevention offalse operation due to these causes. An electroresponsive device of this type should be constructed so that the circuit opened thereby can be reclosed by the tower man or other attendant, only after the protective device is in condition for again opening the circuit in the event that current of the reverse polarity flows when the circuit is reclo'sed.

One of the principal objects of the present invention is to provide an electro-responsive device of this type having the operating characteristics referred to, which isexceedingly simple in its construction, reliable in its operation, comprises but a few and rugged parts and which can be easily'and cheaply manufactured.

Other objects, purposes, and characteristic features of the invention will appear as the description thereof progresses.

In describing the invention in detail, reference will be made to the accompanying drawings, in which Figure 1 is a side elevation of a'protective device embodying the present invention constructed mounted on a panel and enclosed by a cas ing (shown in section parts of which have been broken away for clearness;

Fig. 2 shows a. horizontal section of the device-taken on the line 2-2.of Fig. 1, a portion of the restoring lever having been broken away; r

F 1g; 3 is a' partial side elevation of the protective device, similar to Fig; 1, showing' the armature and contact in their abnormal position; and

Fig. t 'is a view similar to Fig. 3,with theseveral parts in a transient position with the restoring lever in its operative position. 1

Referring to the accompanying drawings,- the protective device embodying the present invention as. illustrated comprises a U-' shaped permanent magnet P, having its one" end bolted to a soft iron extension 1 by a bolt 2Qtl1is same bolt al'sobeing used to support these devices to a panel 3, preferably" of insulating material. A dowel pin l is provided to keep the protective device in a predeterminedposition with respect to the panel 3. i

To the'lower end of the soft iron extensioir 1 is "fastened a core S'terminat'ing in a large circular pole" piece'G, both the core and pole piece preferably being constructed of soft iron or similar magnetic material. On this core 5 is piovideda coil. 7 for purposes more clearly explained hereinafter. Since both the core 5 and extension 1 are constructed ofsoft iron, the magnetic flux due to 'thepermanent magnet will ordinarily divide in certain proportions between these two extending members. i

T h e free end of "the permanent magnet P hasbolted thereto a' triangular or wedgeshaped block 8 fastened by a bolt 9, conveniently called a bearing block, of suitable material, such as tempered steel, to provide a durable frictionless kn'ifeedge bearing for an armature 10., The armature 10 has its right extreme end bent up and down to form agroove fitting directly over the knife edge portioniof the'bearingblock 8. the bearing blockbeing provided with a screw 11 pass ing' through a slot in the armature 10 (see Fig, 2) without contact between its head and the armature. itself. This holds the armature in its adjusted position against extreme. jars andith'e like, the magnetic attraction of iii) too

til

the permanent magnet P maintaining the groove of the armature in cooperative rela tion with the knife edge under ordinary conditions.

To the armature 10 are fixedly secured a pair of contacts 12 of suitable refractory conducting material, but are insulated there- I from by suitable insulating sleeves and washers, as shown. These contacts are electrically connected by the strap conductor 13. It is thus noted that the armature may be moved about its pivotal knife edge support to come into engagement with the pole piece 6 or the extension 1, and that if it is placed in engagement with either of these soft iron members, it will be maintained in such position because the main portion of the magnetic flux of the permanent magnet will pass through the armature.

The soft iron extension 1 has its end broken away or rabbeted to provide a seat for a contact and terminal board 15 secured thereto by suitable screws. In order to suitably adjust the tractive force due to the magnetic fiux when the armature is in its raised position, a suitable adjustable nonmagnetic residual pin 16 has been provided, shown in the form of a screw, which may be adjusted and locked to provide the desired air gap when the armature is. in its normal posit-ion. The threaded hole containing the residual pin 16 is preferably counterbored, as shown. By the provision of this adjustable residual stop, the sensitiveness of the device may be adjusted for the reason that the force necessary to drop the armature depends on the magnetic attraction of the armature into its normal position. The terminal board 15 is provided on its upper face with two grooves spaced a distanceapart corresponding to the spacing of the contacts 12 for accommodating U-sha-ped contact fingers 17 held in place by binding posts 18. These contact fingers are provided at their free ends with contacts 19 of suitable highly refractive conducting material, such as carbon, or the like, and when in their adjusted position are adapted to be engaged by the contacts 12.

The ends of the bearing block 8 are drilled and threaded to receive headed journal pins 20, which are shouldered to provide suitable bearing surfaces for the downwardly ex tending ears 21 of the restoring lever 21. This restoring lever has its one end reduced to form a suitable thumb trigger by which the lever may be moved to its effective position. The other end of the restoring lever 21 terminates in a narrow downwardly eX tending arm extending through a hole in the armature 10 and forming a Z-shaped extension. which is adapted to provide a nonbinding engagement between the restoring lever and the armature when the lever is moved to its operative position. The eX- treme end of this arm is perforated to receive the hooked end of a spring 22, the other end of this spring being hooked into a bracket 23 secured by the bolt 9.

' By looking at Fig. 1, it will be noted that the armature 10 may move from one extreme position to the other without being interfered with by the restoring lever 21. Further, it will be noted that the armature 10 may be restored to its normal position by the actuation of the restoring member 21, a certain amount of clearance between the armature and restoring lever being normally present. This restoring member is, by reason of the tendency of the spring 22, normally held out of engagement with the armature 10. Since it is desirable to be able to restore the protective device embodying this invention to its normal posi tion without permitting the contact to be held in the circuit closing position, a suitable insulating block 25 is screw fastened to the restoring lever 21 as shown, which engages thetwo U-shaped contact fingers 17 and moves these fingers up so that the stationary contacts are out of the range of the contacts 12 during restoring operation.

In order to prevent the operator or tower attendant from plugging the protective device, so to speak, by blocking the armature in its upper position, shorting the binding post 18 or the like, a suitable casing 26 of non-magnetic material is provided for the protective device. Suitable openings are provided for the restoring lever 21, the coil leads and the wires leading to the binding post 18. In order to observe whether the protective device is in its normal or abnormal position, a suitable indicating device comprising and indicator pin 27 is provided. This pin 27 is slidably supported in a hole through the terminal board 15, and is provided at its lower end with a head resting on the conducting strap 13 carried by the armature 10. This indicating pin 27 is prefer ably made of insulating material, so that this indicator may also be used to trip the protective devicewhen it is desired to open the circuit controller without danger oi? injury due to electric shock. It will be noted that the contacts 12 and 19 are disposed in a strong magnetic field, so that the breaking of a circuit by these contacts causes this magnetic field to blowout the are caused by such a circuit interruption.

By looking at Fig. 1, it will be noted that the contacts are in engagement with each other because the armature is in its raised .position against the adjustable residual yin llifi in a direction to aid the passage of flux due to the permanentinagnet through the core 5, the extension 1 and armaturelO will to'a large extent be robbed of magnetic flux because the larger part of the flux now passes from the lefthand endof the permanent magnet]? (assumingthis to be the north pole) through the core 5 to the other pole of this permanentmagnet. This diversion of flux from the extension 1 and the armature causes the armature 10 to drop to its lower position into contact with the polepiece 6, thus breaking the circuit between the stationary contact fingers17 (asshown in Fig; and permanentlyholding the armature in the lower position by both gravity and magnetic flux due to the magnet P. l

It now the operator wishes to again close a circuit of the protective device, he may actuate the restoringlever 21 to its'restoring position as shown in Fig. 4;. During this manipulation, the insulatingblock engages the two contact fingers 17 and moves them up out of the way of the contacts 12,

so that as the armatiire'IO is again attracted by the magnetic flux emanating from extension 1 the circuit between these contact fingers 17 will not be completed. As soon as the operator removes'his thumb from the trigger of the restormg lever "21, the spring 22 returns the restoring member to its nor H1211 position, thereby'reinoving the insulating block 25 and allowing the contact fingers 17 to move downward into engagement with the contacts12. Ifa short circuit, a ground, or a cross is still present, a reverse current will again be set up in the coil 7 thereby again interrupting the circuit at the contact fingers 17 in the same manner as heretofore. I

A reverse current protective device has thus been provided which is adapted to open a circuit if a current in a certain circuit flows in the reverse direction to that in which it normally flows, and in which the circuit closing mechanism cannot be forcibly held in a closed position by a suitable restoring means, although this restoring means permits the device to be restored to its normal condition. I

The device embodying the present invention also provides means whereby the sensitiveness of the device may be adjusted so that it will only be actuated when the reverse currentexceeds a certain minimum.

Having thus shown and described only one specific embodiment of the invention, it is desired to be understood that variouschanges, modifications and adaptions of the specific disclosure maybe made without departing" from the scope of tlief'invention.

For instance, the armature 10 maybe actuated by any other type ot actuating mecha-' nism and after it has been actuated maybe held in positionas shown in the present em:

bodiment, the restoringmeans having the same operating characteristics as shown in the present invention, all without departing from the spirit and the idea oi means under lying the present invention.

l/Vhat I desire to secure by Letters Patent of the United States, is

1. A protective device for safeguarding electric interlocking systems comprising, an

armature, a contact tastenedto said arinature, a stationary contact normally in con tact with said first mentioned contact, electro n'iagnetic means for controlling said armature, and manually operable means for restoring said armature to its'normal position, said restoring means when operated to move the armature to its normal position acting to keep the contactsopen', whereby the contacts are not reclosed to circuit closing position untilthe restoring 9111621115 is moved ijrom its restoring position.

2; A protective device for safeguarding electric interlockingsystems comprising, an arn'iature, a'contact fastened to said armature, a yieldably supported stationarycontact, means for normally maintaining said armature in position to close said contacts, electro-magnetic means for moving said armature to its abnormal position, and manually operable means for restoring said ari'nature to its normal position, said restoring means when operated to 'niove'the armature to its normal position moving said yieldable contact out of range with said first mentioned contact,- whereby the restoring means can not be improperly used to prevent the electro-magnetic means for again opening said contacts after they have been reclosed by the operation of said manually operable means.

8. A protective device for safeguarding interlocking systems for railroads comprising, an armature adapted to be maintained in either its normal or abnormal position magnetically, a contact fastened to said armature, electrically operable means adapted to shift said armature from its normal to its abnormal position, a yieldab'ly supported stationary contact in engagement with said first mentioned contact when the armature is in its normal position, and manually operable means for restoring said armature to its normal position, said manually operable means when in its effective position moving said stationary contact out of contacting range With said first mentioned contact, whereby the contact will not be reclosed until the'restoring means is returned to, its ineffective position.

4. A protective device for safeguarding interlocking systems for railroads comprising, a pivoted member, a contact fastened to said member, a yieldably supported stationary contact, means for normally holding said member in, a position to cause engagement of said contacts, clectro-responsive means adapted to cause said member .to assume an abnormal position, and manually operable means for restoring said member to its normal osition said restorin means when in its effective position maintaining said yieldable contact out of contacting range with said first mentioned contact, whereby said restoring means can not be used for positively maintaining said contact in engagement.

ing means when operated to move the arma-- jture to its normal position acting to keep said circuit closing means open, whereby the-restoring means can not be improperly,

used to prevent said coil from shifting said armature to open said circuit closing means.

6. A. protective device for safeguarding interlocking systems comprising, a permanent magnet having two projecting extensions of soft iron fastened to one of its ends,

a coil on one of said extensions, an armature pivotally supported on the other end of said magnet and adapted to engage either of said extensions-a contact fastened to but insulated from said armature, a yieldably supported stationary contact engaging said first mentioned contact when the armature is in its normal position, and manually operable restoring means for returning said armature to itsnormal position, said restoring means being provided with an insulating block engaging said. yield-able contact and holding it out of contacting range with said first mentioned contact when it is operated, whereby the restoring means can not be used to forcibly maintain said contact in engagement. 7 v

r 7 A protective device for protecting electrical interlocking systems comprising, a'U- shaped permanent magnet, two legs of soft iron extending from one end of said permanent magnet, a winding on one of said legs, an armature pivotally supported by the other end of said permanent magnet having its free end extending betweensaid legs and in either of two extreme positions but normally held in a position away from the leg containing said winding by flux emanating fromthe other leg, means for adjusting the tractive force exerted upon said armature to hold it in its normal position, whereby said last mentioned means determines the amount of current flow necessary in said winding flowing in a certain direction to cause said armature to be attracted to assume the other extreme position, a circuit opened by operation of said armature from normal, and means for restoring said armature to normal which prevents reclosure of said circuit except when in its normalposition.

In testimony whereof I hereby aflix my signature.

JOHN o. LINDNER, 

